This invention relates to circuits and methods for monitoring voltage pulses in electronic circuits, and more particularly, to such circuits and methods for monitoring pulse width modulated waveforms produced by inverter drive logic circuits.
Electronic inverters which convert DC voltage to a constant frequency AC output voltage incorporate inverter drive logic circuits which drive power switching devices to produce a quasi sine wave which is filtered to produce a sine wave output. The inverter drive logic circuit produces several pulse width modulated waveforms which can be combined to produce a single composite transistor-transistor logic (TTL) signal corresponding to all inverter drive logic outputs. A technique is required for testing the inverter drive logic pulse width modulated waveforms and other pulse width modulated waveform patterns. This invention provides circuits and measurement techniques which perform the necessary test function.